Image forming apparatus and media supply apparatus
The integration of a guide member to stabilize the lever member's position in the image forming and medium supply apparatuses ensures precise detection of media type and orientation, addressing operational inconsistencies and improving printing reliability.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- OKI ELECTRIC INDUSTRY CO LTD
- Filing Date
- 2024-12-23
- Publication Date
- 2026-07-03
Smart Images
Figure 2026111212000001_ABST
Abstract
Description
Technical Field
[0005]
[0001] The present disclosure relates to an image forming apparatus and a medium supply apparatus.
Background Art
[0002] There has been proposed an image forming apparatus and a medium supply apparatus having a dial member for indicating a medium size rotatably provided on a medium cassette, a detection switch unit whose output is switched by pressing a pressing portion, and a lever member (auxiliary arm member) including a contact portion and an arm portion supporting the contact portion. By pressing the pressing portion of the detection switch unit through the convex portion on the outer periphery of the dial member, a signal corresponding to the position in the rotation direction of the dial member is obtained (see, for example, Patent Document 1).
Prior Art Documents
Patent Documents
[0003]
Patent Document 1
Summary of the Invention
Problems to be Solved by the Invention
[0004] <00[Means for solving the problem]
[0006] The image forming apparatus disclosed herein comprises an apparatus body including an image forming unit for forming an image on a medium, a medium cassette detachably mounted on the apparatus body, and a guide member. The apparatus body includes a detection switch unit which includes a pressing portion and whose output switches when the pressing portion is pressed, and a lever member which includes a contact portion arranged opposite to the pressing portion, an arm portion supporting the contact portion, and a support portion supporting the arm portion. The medium cassette has a movable member which is movably provided, and the movable member has a protrusion which changes depending on the movement position of the movable member, causing the pressing portion to be pressed via the contact portion. The output of the detection switch unit switches between a pressed state in which the protrusion presses the pressing portion via the contact portion and an unpressed state in which the pressing portion is not pressed, depending on the movement of the movable member. The guide member restricts the movement of the arm portion in a displacement direction intersecting the pressing direction.
[0007] The media supply device of this disclosure comprises a device body to which media is supplied, a media cassette detachably mounted on the device body, and a guide member. The device body includes a detection switch unit which includes a pressing portion and whose output switches when the pressing portion is pressed, and a lever member which includes a contact portion arranged opposite to the pressing portion, an arm portion which supports the contact portion, and a support portion which supports the arm portion. The media cassette has a movable member which is movably provided, and the movable member has a protrusion which changes depending on the movement position of the movable member, causing the pressing portion to be pressed via the contact portion. The output of the detection switch unit switches between a pressed state in which the protrusion presses the pressing portion via the contact portion and an unpressed state in which the pressing portion is not pressed, as the movable member moves. The guide member restricts the movement of the arm portion in a displacement direction intersecting the pressing direction. [Effects of the Invention]
[0008] According to the image forming apparatus and media supply apparatus of this disclosure, the type of media corresponding to the position in the direction of movement of the moving member can be accurately detected. [Brief explanation of the drawing]
[0009] [Figure 1] This is a longitudinal cross-sectional view schematically showing the configuration of the image forming apparatus according to Embodiment 1. [Figure 2] This is a schematic perspective view showing the external appearance of the image forming apparatus according to Embodiment 1. [Figure 3] This is a front view showing an enlarged view of section A of the media cassette in Figure 2. [Figure 4] Figure 2 is a schematic perspective view showing the media cassette being inserted into the main body of the device. [Figure 5] This is a schematic perspective view showing the dial member of the media cassette of the image forming apparatus according to Embodiment 1. [Figure 6] This figure shows the shape and arrangement of the multiple protrusions on the outer circumference of the dial member shown in Figure 5. [Figure 7] This is a perspective view showing the dial setting detection unit (detection switch unit and lever member) of the image forming apparatus according to Embodiment 1. [Figure 8] This is a perspective view showing the dial setting detection unit (dial member, lever member, and guide member) of the image forming apparatus according to Embodiment 1, while the media cassette is being inserted into the main body of the apparatus. [Figure 9] This is a perspective view showing the lever member of the dial setting detection unit of the image forming apparatus according to Embodiment 1. [Figure 10] This is a side view showing the lever member of the dial setting detection unit of the image forming apparatus according to Embodiment 1. [Figure 11] This is a front view showing the guide member of the dial setting detection unit of the image forming apparatus according to Embodiment 1. [Figure 12] This is a side view showing the lever member and guide member of the dial setting detection unit of the image forming apparatus according to Embodiment 1. [Figure 13]This is a perspective view showing the internal structure of the main body of the image forming apparatus according to Embodiment 1. [Figure 14] This is a schematic top view showing the dial setting detection unit (dial member, detection switch unit, lever member, and guide member) of the image forming apparatus according to Embodiment 1 while the media cassette is being inserted into the main body of the apparatus. [Figure 15] This is a schematic diagram showing the dial setting detection unit (dial member, detection switch unit, lever member, and guide member) of the image forming apparatus according to Embodiment 1, while the media cassette is being inserted into the main body of the apparatus. [Figure 16] This is a perspective view showing the dial setting detection unit (dial member, detection switch unit, lever member, and guide member) of the image forming apparatus according to Embodiment 1, while the media cassette is being inserted into the main body of the apparatus. [Figure 17] This is a schematic diagram showing the dial setting detection unit (dial member, detection switch unit, lever member, and guide member) after the media cassette of the image forming apparatus according to Embodiment 1 has been mounted on the main body of the apparatus. [Figure 18] This is a side view showing the dial setting detection unit (dial member, detection switch unit, lever member, and guide member) after the media cassette of the image forming apparatus according to Embodiment 1 has been mounted on the main body of the apparatus. [Figure 19] This is a front view showing the dial setting detection unit (dial member, lever member, and guide member) after the media cassette of the image forming apparatus according to Embodiment 1 has been mounted on the main body of the apparatus. [Figure 20] This is a perspective view showing the dial setting detection unit (dial member, detection switch unit, lever member, and guide member) of the image forming apparatus according to Embodiment 1 after the media cassette has been mounted on the main body of the apparatus. [Figure 21] This is a block diagram showing the configuration of the control system of the image forming apparatus according to Embodiment 1. [Figure 22]A perspective view showing a dial setting detection unit (dial member, detection switch unit, and lever member) when a media cassette is being inserted into the apparatus main body in an image forming apparatus of a comparative example without a guide member. [Figure 23] A perspective view showing a dial setting detection unit (dial member, detection switch unit, and lever member) after a media cassette is attached to the apparatus main body in the image forming apparatus of FIG. 22. [Figure 24] A perspective view showing a dial setting detection unit (dial member, lever member, and guide member) after a media cassette of the image forming apparatus according to Embodiment 2 is attached to the apparatus main body. [Figure 25] A front view showing a dial setting detection unit (lever member and guide member) of the image forming apparatus according to Embodiment 3.
Mode for Carrying Out the Invention
[0010] Hereinafter, a media supply device and an image forming apparatus according to an embodiment will be described with reference to the drawings. The following embodiments are merely examples, and it is possible to appropriately combine the embodiments and appropriately modify each embodiment.
[0011] 《1》Embodiment 1 《1-1》Image Forming Apparatus 1 Figure 1 is a longitudinal cross-sectional view schematically showing the configuration of the image forming apparatus 1 according to Embodiment 1. Figure 2 is a perspective view schematically showing the external appearance of the image forming apparatus 1. The image forming apparatus 1 is a printer having one image forming unit 108 that forms an image on a medium using an electrophotographic process. However, the image forming apparatus 1 may be a color printer having multiple image forming units 108. Also, the image forming apparatus 1 may be a printer that forms an image by a method other than an electrophotographic process (for example, an inkjet method). Furthermore, the image forming apparatus 1 may be a copier, a facsimile machine, a multifunction printer, etc. In addition, the configuration for detecting the position of the rotation direction (movement direction) of a dial member (moving member) set by the user (also called the "dial setting detection unit 20") can also be applied to a medium supply device (also called the "paper feed device") 2 that does not have an image forming function. In other words, the medium supply device 2 is a part of the image forming apparatus 1.
[0012] The image forming apparatus 1 comprises a main body 10, a media cassette 30 (also called a "paper cassette") detachably mounted on the main body 10, and a guide member 41 (part of the dial setting detection unit 20), which will be described later. Multiple media are stacked and stored in the media cassette 30. The media is, for example, recording paper.
[0013] The main body of the device 10 is provided with a dial setting detection unit 20 for detecting the type of media contained in the media cassette 30 (for example, size, whether it is fed vertically or horizontally, etc.) based on the rotational position (i.e., rotational position) of a dial member (a member shown in Figures 5 and 6, described later). "Vertical feeding" of media means that the direction of transport of media is along the longitudinal direction of the media. "Horizontal feeding" of media means that the direction of transport of media is along the short direction of the media. In Embodiment 1, the dial setting detection unit 20 is composed of a dial member 31, a detection switch unit 21, a lever member (also called an "auxiliary arm member") 22, and a guide member 41. Details of the dial setting detection unit 20 will be described later.
[0014] Furthermore, the diagrams show the coordinate axes of the XYZ Cartesian coordinate system to facilitate understanding of the relationships between the figures. The X, Y, and Z axes are the coordinate axes of the depth, width, and height directions of the image forming apparatus 1 and the media supply apparatus 2, respectively. The +X direction is the direction in which the media cassette 30 is inserted into the main body 10 of the apparatus (i.e., the insertion direction) 33, and the -X direction is the direction in which the media cassette 30 is withdrawn from the main body 10 of the apparatus.
[0015] Above the media cassette 30 are a feed roller 104 and a separator 103 (media supply unit) for feeding media one sheet at a time from the multiple media loaded in the media cassette 30 onto the transport path. Downstream of the media fed by the feed roller 104 and separator 103 in the transport direction is a paper feed sensor 105 for detecting that media has been supplied. Downstream of the paper feed sensor 105 are a register roller 106 and a pressure roller 107 (media transport unit) for correcting the skew (diagonal orientation) of the media during transport.
[0016] Downstream of the register roller 106 and the pressure roller 107, an image forming unit (also called an "image drum (ID) unit") 108 is positioned to form a toner image (developer image). Above the image forming unit 108, a print head (also called an "exposure device") 110 is positioned to form an electrostatic latent image on the photoreceptor drum 112 of the image forming unit 108. Below the image forming unit 108, a transfer roller (also called a "transfer unit") 109 is positioned to transfer the toner image formed in the image forming unit 108 to a medium. Furthermore, a passage sensor 111 is provided upstream of the image forming unit 108 to determine the timing for starting the formation of the toner image.
[0017] The image forming unit 108 includes a photoreceptor drum 112 as an image carrier that holds an electrostatic latent image, a charging roller 113 as a charging member that uniformly charges the photoreceptor drum 112 to a predetermined potential (for example, a predetermined negative potential), and a developing roller 114 as a developer carrier that develops the electrostatic latent image formed on the photoreceptor drum 112 by the print head 110 to form a toner image.
[0018] Downstream of the image forming unit 108, a fixing device is arranged to fix the toner image transferred onto the medium to the medium. The fixing device has a heat roller 115 and a backup roller 116 that sandwich the medium and heat and pressurize it.
[0019] Downstream of the fixing unit, an ejection roller 117 and a driven roller 118 are arranged to transport the medium on which the toner image has been fixed. Further downstream of the ejection roller 117 and the driven roller 118, an ejection roller 120 and a driven roller 121 are provided to eject the medium to an ejection stacker 119 located at the top of the main body 10 of the device. The axial directions of the photoreceptor drum 112 and the developing roller 114 of the image forming unit 108 are parallel to the Y direction.
[0020] 《1-2》Dial setting detection unit 20 Next, a dial setting detection unit 20 will be described, which includes a configuration for detecting the setting of a dial member 31 indicating the type of media (e.g., size) contained in the media cassette 30 (i.e., the position of the movable member in the direction of movement, for example, the position of the dial member 31 in the direction of rotation) using a detection switch unit 21 of the device body 10. The movable member changes its protrusion in the direction of pressing, which causes the pressing portion to press down via the contact portion, depending on the position of the movable member in the direction of movement (movement position). In this embodiment, the position in the direction of rotation of the dial member 31 as a movable member (rotation position) means the position in the direction of rotation 34 of one or more protrusions 313a on the outer circumference of the dial member 31 (including the arrangement of multiple protrusions 313a, i.e., the arrangement of multiple recesses). As described above, the media cassette 30 having a media storage portion for containing media is detachably mounted on the lower part (mounting portion) of the device body 10. However, the structure of the device body 10, the position and structure of the media cassette 30 are not limited to the illustrated examples.
[0021] Figure 3 is a front view showing an enlarged view of part A of the media cassette 30 in Figure 2. Figure 4 is a schematic perspective view showing the media cassette 30 in Figure 2 in the process of being inserted into the main body 10 of the device (i.e., moving in the insertion direction 33). An opening 303 is formed in the front portion 302 of the gripping portion 301 of the media cassette 30 at a position opposite the display portion 311 of the dial member 31. The moving member moves in a predetermined direction by user operation. For example, the dial member 31 rotates around the rotation axis 310 by user operation. This allows the user to visually confirm the type of media displayed on the display portion 311 of the dial member 31 from outside the media cassette 30 through the opening 303.
[0022] Figure 5 is a perspective view showing the configuration of a dial member 31 provided on a media cassette 30 of an image forming apparatus 1. Figure 6 is a diagram showing the shape and arrangement of the convex portions 313a on the outer circumference of the dial projection 313 of the dial member 31 in Figure 5. The dial member 31 is a substantially cylindrical member and has a rotational axis 310 parallel to the Y direction, and the rotational axis 310 is rotatably supported on opposing walls of the media cassette 30. In addition, recesses 313b are formed between adjacent convex portions 313a on the outer circumference of the dial projection 313. However, the shape of the dial member 31 is not limited to that shown.
[0023] The dial member 31 is a combination of a roughly cylindrical display portion 311, a roughly disc-shaped rotating locking portion 312, and a roughly disc-shaped dial projection portion 313, all arranged coaxially and integrally. These components rotate integrally around the rotational central axis 310.
[0024] As shown in Figures 5 and 6, multiple markings indicating the type of media (size, orientation, etc.) are arranged at equal intervals on the outer circumferential surface of the display section 311 of the dial member 31. Here, each of the multiple equal divisions of the outer circumferential surface of the display section 311 is marked with a mark indicating the size of the media (such as A4, A5, B5) and the orientation of the media (such as a mark indicating vertical or horizontal feed).
[0025] The rotation locking portion 312 of the dial member 31 is for locking the dial member 31 at a predetermined rotation angle (rotation position), and consists of multiple recesses 312a arranged at equal intervals in the circumferential direction on the outer circumferential surface which is substantially along the outer circumferential surface of the display unit 311, which serve as engaging portions. The rotation locking portion 312 is locked at one of several rotation angles by a locking portion (not shown) which is an angle-holding member arranged inside the media cassette 30.
[0026] Figure 7 is a perspective view showing the dial setting detection unit 20 (detection switch unit 21 and lever member 22) of the image forming apparatus 1. Figure 8 is a perspective view showing the dial setting detection unit 20 (dial member 31, lever member 22, and guide member 41) while the media cassette 30 of the image forming apparatus 1 is being inserted into the apparatus body 10. The dial setting detection unit 20 consists of a dial member 31 (shown in Figures 9 and 10 described later), a detection switch unit 21 (shown in Figures 14 to 20 described later), a lever member 22 (shown in Figures 9, 10, 14 to 20 described later), and a guide member 41 (shown in Figures 11, 12, 14 to 20 described later).
[0027] Figure 9 is a perspective view showing the lever member 22 of the dial setting detection unit 20 of the image forming apparatus 1. Figure 10 is a side view showing the lever member 22. Figure 11 is a front view showing the guide member 41 of the dial setting detection unit 20 of the image forming apparatus 1. Figure 12 is a side view showing the lever member 22 and the guide member 41. Figure 13 is a perspective view showing the inside of the main body 10 of the image forming apparatus 1.
[0028] As shown in Figures 9 and 10, the lever member 22 includes a contact portion 222 positioned opposite the pressing portion 211 (shown in Figure 14) of the detection switch portion 21, an arm portion 221 supporting the contact portion 222, and a support portion 220 provided on the opposite side of the contact portion 222, sandwiching the arm portion 221. The arm portion 221 is, for example, an elastically deformable member. The support portion 220 has a positioning hole 220a as a positioning portion and is fixed to the main body structure (frame structure) of the device body portion 10. The arm portion 221 is an elastically deformable deformable portion D that supports the contact portion 222 so that it can move mainly in the X direction. The arm portion 221 has a curved structure as shown in Figure 10. The arm portion 221 is formed of an elastic member such as metal, for example. The shape of the arm portion 221 is not limited to that shown. The contact portion 222 is, for example, a non-deformable portion C, and is configured to shift (i.e., move) in the X direction due to the deformation of the arm portion 221. The support portion 220 is fixed to a predetermined position 15 of the device body portion 10 by parts such as screws. Figure 9 shows multiple (4) arm portions 221 and multiple (4) contact portions 222, but the number of these may be one.
[0029] As shown in Figures 11 and 12, the guide member 41 has a fixed portion 410 having a positioning hole 410a and a plurality of restricting portions 411 extending from the fixed portion 410 as guide portions. In the example in Figure 11, five restricting portions 411 are shown, but the number of restricting portions 411 may be one. Also, the number of restricting portions 411 may be two, three, four, or six or more. As shown in Figure 12, the guide member 41 is positioned so that the fixed portion 410 overlaps the support portion 220 of the lever member 22 and is fixed to a predetermined position on the device body 10 (for example, position 15 in Figure 13) by parts such as screws. However, the guide member 41 and the lever member 22 may be fixed to the predetermined position on the device body 10 by other means. When the guide member 41 and the lever member 22 are fixed to the main body 10 of the device, the restricting portion 411 of the guide member 41 is positioned to contact either the side portion 221a (Figure 9) or the side portion 221b (Figure 9) of the arm portion 221, thereby restricting (limiting) the movement (displacement) of the arm portion 221 in the Z direction. In other words, the restricting portion 411 of the guide member 41 is positioned to face the side portion 221a (Figure 9) of the arm portion 221 with a predetermined gap (clearance), or to face the other side portion 221b (Figure 9) of the arm portion 221 with a predetermined gap, or to face the sides 221a and 221b (Figure 9) of the arm portion 221 with a predetermined gap. The restricting portion 411 of the guide member 41 is attached to the top and bottom of the arm portion 221 of the lever member 22, and a clearance is provided between the arm portion 221 and the restricting portion 411. The regulating portion 411 does not come into contact with the dial member 31 and is located above and below the range that includes the non-deformable portion of the arm portion 221.
[0030] Figure 14 is a schematic top view showing the dial setting detection unit 20 (dial member 31, detection switch unit 21, lever member 22, and guide member 41) while the media cassette 30 of the image forming apparatus 1 is being inserted into the main body 10 of the apparatus. Figure 15 is a schematic diagram showing the dial setting detection unit 20 (dial member 31, detection switch unit 21, lever member 22, and guide member 41) while the media cassette 30 of the image forming apparatus 1 is being inserted into the main body 10 of the apparatus. Figure 16 is a perspective view showing the dial setting detection unit 20 (dial member 31, detection switch unit 21, lever member 22, and guide member 41) while the media cassette 30 of the image forming apparatus 1 is being inserted into the main body 10 of the apparatus.
[0031] Figure 17 is a schematic diagram showing the dial setting detection unit 20 (dial member 31, detection switch unit 21, lever member 22, and guide member 41) after the media cassette 30 of the image forming apparatus 1 has been mounted on the main body 10 of the apparatus. Figure 18 is a side view showing the dial setting detection unit 20 (dial member 31, detection switch unit 21, lever member 22, and guide member 41) after the media cassette 30 of the image forming apparatus 1 has been mounted on the main body 10 of the apparatus. Figure 19 is a front view showing the dial setting detection unit 20 (dial member 31, lever member 22, and guide member 41) after the media cassette 30 of the image forming apparatus 1 has been mounted on the main body 10 of the apparatus. Figure 20 is a perspective view showing the dial setting detection unit 20 (dial member 31, detection switch unit 21, lever member 22, and guide member 41) after the media cassette 30 of the image forming apparatus 1 has been mounted on the main body 10 of the apparatus.
[0032] As shown in Figures 14, 15, 17, and 18, the detection switch unit 21 has a plurality of switches S1, S2, S3, and S4. However, the number of switches included in the detection switch unit 21 is not limited to four, but may be any other number (for example, one or five or more). Each of the switches S1, S2, S3, and S4 switches its output to a pressed state (e.g., on) or an unpressed state (e.g., off) by pressing or not pressing the pressing portion 211. The lever member 22 includes a contact portion 222 positioned opposite the pressing portion 211, a deformable arm portion 221 that supports the contact portion 222, and a support portion 220. The dial member 31 is rotatably mounted on the media cassette 30 around the rotational axis 310 and includes a radially outward-projecting protrusion 313a. The protrusion 313a moves due to user operation (e.g., rotation by rotational operation), and depending on the position of the rotational direction 34 of the protrusion 313a, the protrusion 313a presses the pressing portion 211 in the pressing direction via the contact portion 222. At this time, the guide member 41 restricts the deformation of the arm portion 221 in the displacement direction (Z direction), which is a direction intersecting the pressing direction (e.g., a direction perpendicular to both the rotational direction 34 and the radial direction), so that the contact portion 222 does not shift in the Z direction to a position where it does not face the pressing portion 211 of the detection switch portion 21. Therefore, as shown in Figures 17 and 20, the protrusion 313a of the dial member 31 can reliably press the pressing portion 211 of the detection switch portion 21 of the lever member 22.
[0033] 《1-3》Control System Figure 21 is a block diagram showing the configuration of the control system of the image forming apparatus 1. The control unit 100, which is responsible for controlling the image forming apparatus 1, is equipped with a processor, ROM (Read Only Memory) and RAM (Random Access Memory) as storage devices, input / output ports, timers, etc., and receives print data and control commands from a host device 101 such as a personal computer to control the operation of the image forming apparatus. The interface (I / F) control unit 130 transmits information about the image forming apparatus 1 (such as printer information) to the host device 101, analyzes commands sent from the host device 101, and processes data sent from the host device 101.
[0034] The charging voltage control unit 131 applies a charging voltage to the charging roller 113 of the image forming unit 108 in order to uniformly charge the surface of the photoreceptor drum 112 of the image forming unit 108, as instructed by the control unit 100. The head control unit 132 drives the print head 110 according to the print data in order to expose the surface of the photoreceptor drum 112 and form an electrostatic latent image, as instructed by the control unit 100. The developing voltage control unit 133 applies a developing voltage to the developing roller 114 of the image forming unit 108 in order to develop the electrostatic latent image on the photoreceptor drum 112, as instructed by the control unit 100.
[0035] The transfer voltage control unit 134 applies a transfer voltage to the transfer roller 109 in order to transfer the toner image formed on the surface of the photoreceptor drum 112 to the medium, as instructed by the control unit 100. The fuser control unit 135 controls the power supply to the heater 139 built into the heat roller 115 on and off based on the temperature detected by the thermistor 140, which detects the temperature of the fuser unit (115, 116). The paper feed transport control unit 136 controls the drive of the feed motor 141 and the transport motor 142 in order to be instructed by the control unit 100. The feed motor 141 rotates the feed roller 104, and the transport motor 142 rotates the transport roller 118 and the discharge rollers 117 and 120.
[0036] The image formation drive control unit 137 drives the image drum (ID) motor 143, which rotates the photoreceptor drum 112 and the developing roller 114, according to instructions from the control unit 100. The charging roller 113 rotates in accordance with the photoreceptor drum 112. The fuser drive control unit 138 drives the fuser drive motor 144, which rotates the heat roller 115, according to instructions from the control unit 100. The backup roller 116 rotates in accordance with the heat roller 115.
[0037] The control unit 100 also receives detection signals from the detection switch unit 21, i.e., ON / OFF signals from the n press-button units 211. Based on the detection signals from the detection switch unit 21, the control unit 100 corresponds to a determination unit that determines the type of media in the media cassette 30.
[0038] 《1-4》 Operation of the image forming apparatus 1 The operation of the image forming apparatus 1 will be explained with reference to Figures 1 and 2. When the control unit 100 of the image forming apparatus 1 receives a print instruction and print data from the host device 101, it starts the image forming operation. First, the paper feed transport control unit 136 drives the feed motor 141, and the feed roller 104 rotates to feed the media in the media cassette 30 onto the transport path.
[0039] The medium, fed onto the transport path by the feed roller 104, passes through the paper feed sensor 105 and reaches the nip portions of the register roller 106 and pressure roller 107. The paper feed transport control unit 136 drives the transport motor 142 at a predetermined timing based on the detection signal from the paper feed sensor 105, causing the register roller 106 and pressure roller 107 to start rotating. After the medium's skew is corrected by the register roller 106 and pressure roller 107, it is transported toward the image forming unit 108. The medium passes through the passage sensor 111 and reaches the image forming unit 108.
[0040] Based on the detection signal from the passage sensor 111, the control unit 100 forms a toner image in the image forming unit 108 as follows: The image forming drive control unit 137 drives the ID motor 143, causing the photoreceptor drum 112 and the developing roller 114 to rotate. The charging roller 113 is subjected to a charging voltage by the charging voltage control unit 131 and rotates in conjunction with the photoreceptor drum 112, uniformly charging the surface of the photoreceptor drum 112. Furthermore, the print head 110 is driven by the head control unit 132, exposing the surface of the photoreceptor drum 112 to form an electrostatic latent image. The developing roller 114 is subjected to a developing voltage by the developing voltage control unit 133, developing the electrostatic latent image on the surface of the photoreceptor drum 112 with toner to form a toner image.
[0041] A transfer voltage is applied to the transfer roller 109 by the transfer voltage control unit 134, and as the medium passes through the nip between the photoreceptor drum 112 and the transfer roller 109, the toner image on the surface of the photoreceptor drum 112 is transferred to the medium. The medium on which the toner image has been transferred is transported to the fixing unit (115, 116). The toner image transferred onto the medium is heated and pressurized by the heat roller 115 and the backup roller 116 to fix it to the medium. The medium on which the toner image has been fixed is transported by the discharge roller 117 and the driven roller 118, and the discharge roller 120 and the driven roller 121, and discharged to the discharge stacker 119.
[0042] Next, the setting and detection of the media type will be described. The detection switch unit 21 has one or more (four in this case) push-in parts (push levers) 211, and multiple media types can be set by combinations of pressing the push-in parts 211. The media type (for example, size and feeding direction) is displayed on the display part 311 of the dial member 31. Before the media cassette 30 is installed in the main unit 10 of the device, the user touches the exposed part of the dial projection 313 (the part indicated by the symbol B in Figure 14) to rotate the dial member 31 and set the media type display.
[0043] In Figures 15 and 17, the detection switch section 21 includes switches S1, S2, S3, and S4, each having four pressable parts 211. The dial member 31 also has multiple protrusions 313a as the dial projection 313.
[0044] When the media cassette 30 is not installed in the main body 10 of the device, the dial projection 313 of the dial member 31 does not reach the lever member 22 (contact portion 222), so none of the pressing portions 211 of the detection switch portion 21 are pressed down. In other words, switches S1, S2, S3, and S4 are all OFF.
[0045] The control unit 100 of the image forming apparatus 1 determines that no media cassette 30 is installed if all switches S1, S2, S3, and S4 are OFF. The control unit 100 of the image forming apparatus 1 determines the type of media based on the dial setting of the media cassette 30, depending on the combination of ON or OFF of switches S1, S2, S3, and S4.
[0046] Furthermore, as shown in Figure 13, the amount of protrusion (amount of protrusion toward the dial member 31) of the contact portions 222 of the two arm portions 221 at the upper and lower ends of the lever member 22 is greater than the amount of protrusion of the contact portions 222 of the two central arm portions 221. This is because the dial projection 313 contacts the lever member 22 in the radial direction of rotation, causing the dial projection 313 to protrude more towards the detection switch portion 21 at the center than at the upper and lower ends.
[0047] Effect 1-5 Figure 22 is a perspective view showing the dial member 31, detection switch unit 21, and lever member 22 in an image forming apparatus of a comparative example that does not have a guide member, while the media cassette 30 is being inserted into the main body 10 of the apparatus. Figure 23 is a perspective view showing the dial member 31, detection switch unit 21, and lever member 22 in the image forming apparatus of the comparative example of Figure 22 after the media cassette 30 has been mounted in the main body 10 of the apparatus. As shown in Figure 23, in the image forming apparatus of the comparative example that does not have a guide member, the contact portion 222 of the lever member 22 may shift in the Z direction, and the contact portion 222 may shift in the Z direction to a position where it does not face the pressing portion 211 of the detection switch unit 21. In this case, the convex portion 313a of the dial member 31 cannot press down the pressing portion 211 of the detection switch unit 21 of the lever member 22.
[0048] In contrast, in the image forming apparatus 1 and media supply apparatus 2 according to Embodiment 1, the contact portion 222 of the lever member 22 is restricted from shifting in the Z direction by the guide member 41, so that the contact portion 222 does not shift in the Z direction to a position where it does not face the pressing portion 211 of the detection switch unit 21. Therefore, the convex portion 313a of the dial member 31, which is rotatably provided on the media cassette 30, can reliably press the pressing portion 211 of the detection switch unit 21 via the contact portion 222 of the lever member 22.
[0049] (2) Embodiment 2 Figure 24 is a perspective view showing the relationship between the dial member (movable member) 31, the detection switch unit 21, the lever member 22, and the guide member 42 after the media cassette 30 of the image forming apparatus (or media supply apparatus) according to Embodiment 2 has been mounted on the main body 10 of the apparatus. Embodiment 2 differs from Embodiment 1, in that the guide member 42 is directly mounted on the main body 10 of the apparatus, in which the guide member 41 is superimposed on the support unit 220 of the lever member 22 and fixed in a predetermined position on the main body 10. Since the guide member 42 includes a restricting unit 421 positioned to restrict the Z-direction displacement of the arm unit 221 of the lever member 22, the type of media corresponding to the rotational position of the dial member 31, which is the moving position of the movable member (i.e., the rotational position of the dial member 31 set by the user), can be accurately detected by the detection switch unit 21. With respect to all other aspects, Embodiment 2 is the same as Embodiment 1.
[0050] (3) Embodiment 3. Figure 25 is a front view showing the lever member 22 and guide member 43 of the image forming apparatus (or media supply apparatus) according to Embodiment 3. Embodiment 3 differs from Embodiments 1 and 2 in that the guide member 43 is attached to the lever member 22. Since the guide member 43 includes a restricting portion positioned to restrict the Z-direction displacement of the arm portion 221 of the lever member 22, the type of media corresponding to the rotational position of the dial member 31, which is the movement position of the moving member (i.e., the rotational position of the dial member 31 set by the user), can be accurately detected by the detection switch portion 21. With respect to all other aspects, Embodiment 3 is the same as Embodiments 1 or 2.
[0051] (4) Modified form In embodiments 1 to 3, a device was described that detects the type of medium corresponding to the rotational position of the dial member 31 (i.e., the rotational position of the dial member 31 set by the user) using a detection switch unit 21 having one or more switches (for example, four switches). However, this device may also be a medium supply device 2 (Figure 1).
[0052] The modified media supply device 2, similar to the configuration of the image forming apparatus in Figure 14, comprises a device body 10 to which the media is supplied, a media cassette 30 that can be attached to and detached from the device body 10, and a guide member 41. The device body 10 has a detection switch unit 21 whose output is switched by pressing a pressing portion 211 in the pressing direction, and a lever member 22 which includes a contact portion 222 positioned opposite the pressing portion 211, an arm portion 221 that supports the contact portion 222, and a support portion 220 provided on the opposite side of the contact portion 222 with the arm portion 221 in between. The media cassette 30 has a cassette body capable of accommodating media and a dial member 31 as a movable member. The dial member 31 is mounted on the cassette body containing the media so as to be rotatable (movable), and includes a protrusion 313a that protrudes in a predetermined direction (for example, protruding radially outward from the cylindrical dial member), and the dial member 31 has a dial member 31 in which the protrusion 313a switches the pressing portion 211 to a pressed state or an unpressed state via the contact portion 222 depending on the rotation position (movement position) of the protrusion 313a in the rotation direction 34 of the rotation operation (movement in the movement direction of the movement operation). The guide member 41 restricts (limits) the deformation of the arm portion 221 in the shear direction (Z direction) which is a direction that intersects the pressing direction that presses the pressing portion 211 (for example, a direction perpendicular to both the rotation direction (movement direction of the movement member) 34 and the radial direction of the dial member 31). In this case as well, if the guide member 41 is positioned to restrict the displacement of the arm portion 221 of the lever member 22 in a direction parallel to the Z axis, the type of medium corresponding to the position of the rotation direction 34 of the dial member 31 can be accurately detected by the detection switch unit. [Explanation of Symbols]
[0053] 1 Image forming apparatus, 2 Media supply device, 10 Main body of apparatus, 21 Detection switch unit, 211 Pressing part (pressing lever), 22 Lever member (auxiliary arm member), 220 Support part, 221 Arm part, 221a, 221b Side parts, 222 Contact part, 30 Media cassette, 31 Dial member (moving member), 311 Display unit, 312 Rotation locking part, 313 Dial projection, 313a Convex part, 313b Recessed part, 33 Insertion direction, 34 Rotation direction (movement direction), 41, 42, 43 Guide members, 410 Fixing part, 411 Regulating part, 100 Control unit.
Claims
1. The apparatus includes an image forming unit that forms an image on a medium, A media cassette that is detachably attached to the main body of the device, Guide member and It has, The main body of the device is, A detection switch unit including a pressable portion, the output of which is switched by pressing the pressable portion, A lever member including a contact portion arranged opposite to the pressing portion, an arm portion supporting the contact portion, and a support portion supporting the arm portion, It has, The media cassette has a movable member that is provided to be movable, The moving member has a protrusion that changes depending on the position of the moving member, causing it to press down the pressing portion via the contact portion, in the pressing direction. The output of the detection switch unit switches between a pressed state, where the protrusion presses down the pressing portion via the contact portion, and an unpressed state, where the pressing portion is not pressed, as the moving member moves. The guide member restricts the movement of the arm portion in the displacement direction intersecting the pressing direction. An image forming apparatus characterized by the following:
2. The guide member has a restricting portion formed to face one or both sides of the arm portion in the direction of displacement. The image forming apparatus according to feature 1.
3. A clearance is provided between the guide member and the side portion of the arm. The image forming apparatus according to feature 2.
4. The guide member is positioned so that the side portion of the arm portion contacts the restricting portion, thereby restricting the deformation of the arm portion in the displacement direction. The image forming apparatus according to feature 2.
5. The support portion of the lever member and the fixing portion of the guide member are fixed to the main body of the device in overlapping positions. The image forming apparatus according to any one of claims 1 to 4.
6. The guide member is provided as part of the main body of the device. The image forming apparatus according to any one of claims 1 to 4.
7. The guide member is fixed to the lever member. The image forming apparatus according to any one of claims 1 to 4.
8. The guide member restricts the movement of the lever member in the displacement direction within a range in which the protrusion does not deform when it presses against the contact portion. The image forming apparatus according to any one of claims 1 to 4.
9. The aforementioned arm portion is elastically deformable, The moving member is a rotatable cylindrical dial member, The aforementioned protrusion extends radially outward from the dial member. As the dial member moves in the rotational direction, the protrusion switches between a pressed state in which it presses the pressing portion via the contact portion and a non-pressed state in which it does not press the pressing portion. The guide member restricts the movement of the arm portion in the downward direction, which is the sliding direction that intersects both the rotational direction and the radial direction via the contact portion. The image forming apparatus according to any one of claims 1 to 4.
10. The main body of the device to which the medium is supplied, A media cassette that is detachably attached to the main body of the device, Guide member and It has, The main body of the device is, A detection switch unit including a pressable portion, the output of which is switched by pressing the pressable portion, A lever member including a contact portion arranged opposite to the pressing portion, an arm portion supporting the contact portion, and a support portion supporting the arm portion, It has, The media cassette has a movable member that is provided to be movable, The moving member has a protrusion that changes depending on the position of the moving member, causing it to press down the pressing portion via the contact portion, in the pressing direction. The output of the detection switch unit switches between a pressed state, where the protrusion presses down the pressing portion via the contact portion, and an unpressed state, where the pressing portion is not pressed, as the moving member moves. The guide member restricts the movement of the arm portion in the displacement direction intersecting the pressing direction. A media supply device characterized by the following features.